What is the sequence of operation for a dual element electric water heater?
The basic operation of a two thermostat system (upper and lower) on an electric water heater of 240 volt supply is as follows: Only one element will come on at any one time. This is known as a flip/flop system. On a 240 volt water heater, there will always be 120 volts to both elements. The thermostat will direct the second leg of the 120-volts to the element to complete the 240 volts required to energize the element. Initial start up: When the tank is full of cold water, the upper thermostat will take priority and heat up the top portion of the water to the setting of the thermostat. Once that temperature has been reached, the thermostat will then flip power down to the lower thermostat. The lower thermostat switch will close and heat up the bottom portion of the tank until the water is heated to the setting of that thermostat. At this point the tank will be full of hot water. Normal Operation: When hot water is being used, cold water enters the bottom of the heater (either through th
